Explosive.



,UNITED STA PA 1i";

CLIFFORD A. WOODIBURY, OF CHESTER, PENNSYLVANIA, ASSIGNOR T0 E. I. DU PONT DE NEMOUBS POWDER COMPANY, OFv WILMINGTON, DELAWARE,

NEW JERSEY.

A CORPORATION or ExPLosrvE.

1,124,679. No Drawing. Application filed May 18, 1912,

To all whom it may concern Be it known that I, CLIFFORD A. Woon- BURY, of Chester, in the county of Delaware, and in the State of Pennsylvania, have invented a certain new and useful Improvement in Explosives, and do hereby declare that the following is a full, clear, and exact description thereof.

The object of my invention has been to provide an explosive having approximately a specified velocity of detonation, and particularly a relatively low velocity of detonation, and to such ends my invention con sists in the explosive hereinafter specified.

As an embodiment of my invention by which to illustrate its principle, I have chosen an explosive which is adapted for use in the mining of coal. Such explosive may have the following formula: nitrate of ammonia 80%,nitro-glycerin 10%, absorbent (such as wood pulp) 10%.

An explosive of the above stated formula, using ammonium nitrate in the form ordinarily. produced, has a relatively high velocity of detonation so that when used in the mining of coal it shatters the coal and breaks it up too small for sale as lump coal. The ammonium nitrate ordinarily used in explosives of this kind is so fine that from- 50 to 90%.will pass a 60-mesh sieve, and 25% or more would ordinarily pass a 100'- mesh sieve. An explosive of the above composition made with this ordinary type of ammonia has a velocity of detonation of from 3000 to 3600. I desire to produce an explosive having said formula but which has a low velocity of detonation so as to successfully. produce lump coal. I have found that by making the said explosive of ammonium nitrate having relatively coarse grains, I am able to reduce the velocity of detonation to the desired point.. For exam ple, if I use an ammonium nitrate of such fineness that not more than 17% by Weight passes a 60-mesh sieve, I obtain an explosive whose velocity of detonation is substantially lower than an explosive made with usual ammonium nitrate. The velocity of this explosive will run from 1800 to 2600 meters per second, and on account of this low velocity the explosive is of great advan- Specification of Letters Patent.

Patented Jan. 12, 1915.

Serial No. 698,346. Renewed June 9, 1914. Serial No.

tage for work in which a slow explosive is such as might be obtained by grinding ammonium nitrate or by certain methods of crystallization. While I have described my invention above in detail, I wish it to be understood that many changes may be made in the details thereof without departing from the spirit of my invention.

By the term relatively large, as applied to the size of the grains or particles inthe claims, is meant grains of nitrate of ammonia substantially as large or larger than grains of which not more than approximately seventeen per cent. by weight will pass through a sixty mesh sieve. By the term relatively low velocity of detonation appearing in the claims, is meant a velocity of detonation substantially lower than twenty-seven hundred meters per second- I claim:

1. An explosive having a relatively low velocity of detonation, comprising nitrate of ammonia in relatively large particles.

2. An explosive having a relatively low velocity of detonation, comprising nitrate of ammonia in relatively large globular grains.

3. An explosive having a relatively low velocity of detonation and comprising nitrate of ammonia, nitroglycerin and an absorbent, the nitrate of ammonia being in the form of relatively large particles.

4. An explosive having a relatively low velocity of detonation, and comprising nit-rate of ammonia, nitroglycerin, and an absorbent, the nitrate of ammonia being in the form of relatively large globular grains.

In testimony that I claim the foregoing I have hereunto set my hand.

CLIFFORD A. WOODBURY.

Witnesses C. R. Mensa, FREDERICKLOREN GALLUP. 

